In recent years, vehicles are equipped with optical sensors such as a camera, a laser or the like, and water drops and/or dirt on the lenses of those sensors are removed by jetting a fluid toward the lenses of those sensors. Such a configuration is disclosed in, for example, a patent document in the following.    (PATENT DOCUMENT 1) Japanese Patent Laid-Open No. 2001-171491
For this type of optical sensors disposed on the vehicle, it is assumed that snow and/or ice is accumulated thereon when the vehicle is used in cold/snowy countries, and, thus it is assumed that the sights of those sensors are obstructed by the accumulated snow or ice that hangs down from the above of those sensors in an eaves shape, to get in front of the lens of the optical sensor or to attach on the lens surface.